Median raphe cyst: A clinically challenging diagnosis.

Median raphe cyst is an uncommon developmental anomaly that can develop anywhere along the midline of the external genitals. Only a few hundred cases have been published in the English literature and the lack of awareness of this entity can lead to confusion and misdiagnosis. We report here a case of median raphe cyst located in the midline of the anterior scrotum of a 35- year-old man. Clinically, the patient presented with a scrotal mass increasing substantially in size over two days associated with tenderness, skin erythema, and scrotal pain. Radiologic interpretation of a sonogram and computed tomography scan suggested a thrombosed vessel. The patient was diagnosed with septic thrombophlebitis associated with overlying cellulitis. Despite conservative therapy with antibiotics, the patient developed pyrexia, tachycardia, and leukocytosis prompting surgical excision of the lesion. Histopathologic examination revealed an infected median raphe cyst. The cyst wall was lined by a stratified epithelium that included numerous Alcian blue positive goblet cells. The epithelial cells showed reactive changes with infiltration by numerous neutrophils. Our objective is to bring attention to and thereby facilitate the diagnosis of this unusual entity.

Immunostaining for MART-1 in the interpretation of problematic intra-epidermal pigmented lesions.

The histopathologic distinction between pigmented actinic keratosis (PAK) and atypical junctional melanocytic proliferations (AJMP) is a common problem, and it is one with meaningful clinical significance. Previous publications have suggested that Melanocyte Antigen Related to T-cells-1 (MART-1)--a melanocytic marker related to host immune response--was not useful in making this interpretative separation. To revisit that assertion, the authors selected 68 specimens that concerned the diagnosis of PAK vs. AJMP. The degree of morphologic difficulty attached to each case was rated semiquantitatively using a three-tiered scale, and interpretative problems were caused by cytologic similarity between atypical keratinocytes and aberrant melanocytes, obscuring lichenoid inflammation, subepidermal fibrosis, and an absence of clearly defined cell nests at the dermoepidermal junction. Each biopsy sample was immunostained for MART-1 (using antibody clone A103) with azure-B counterstaining; the principal criterion for a diagnosis of AJMP was that of confluent cellular positivity over at least 1 high-power (x400) microscopic field, in conjunction with nested cell growth. The specimens were then re-examined diagnostically. Immunostaining definitely improved interpretative certitude in 65 examples (96% effectiveness); the final diagnosis was that of PAK for 21 lesions and AJMP for 47. Three specimens--all of which represented AJMP--did not benefit by MART-1 staining. It is concluded that MART-1 immunostaining with azure-B counterstaining is a useful adjunct in the interpretation of problematic intra-epidermal pigmented lesions.

alpha-methylacyl coenzyme A racemase is immunoreactive in extramammary Paget disease.

alpha-Methylacyl-coenzyme A racemase (AMACR) has become a common tool in the diagnosis of morphologically difficult prostatic carcinoma and often is used in combination with the basal cell markers p63 and 34betaE12. Outside this context, applications have been limited. Although initially considered a specific marker of prostatic carcinoma, immunoreactivity for AMACR has been found in a variety of other neoplasms. We report findings in 21 cases of extramammary Paget disease (EMPD), a neoplasm not previously reported to show AMACR immunoreactivity. We found immunoreactivity for AMACR in 15 (71%) of 21 EMPD cases overall, in 5 (56%) of 9 cases in women, and in 10 (83%) of 12 cases in men. AMACR immunoreactivity is a common finding in EMPD in men and women.